1. Field of Invention
The present invention relates to an optical connector, an optical element holding structure, and a structure of a mount section of an optical connector to be employed in the field of optical communication such as that used in office automation, factory automation, and vehicle-mounted equipment.
2. Description of Related Art
An optical connector which is to be fixedly mounted on a mount board while incorporating optical elements has been improved in terms of a noise resistance characteristic of optical elements for withstanding external noise. In order to suppress radiation noise origination from the optical elements, the optical elements are built into a connector housing while being housed in a shielding shell made of highly conductive material, such as metal.
FIGS. 31 and 32 show conceivable constructions for grounding a shielding shell of an optical connector of this type.
In an optical connector 101 shown in FIG. 31, a lead terminal 106 is provided at right angles on a shielding shell 102 for sheathing an optical element D, so as to project downward beyond a connector housing 105. While the optical connector 101 is mounted on a mount board 108, the lead terminal 106 penetrates through the mount board 108 and is soldered to a trace formed on a lower surface of the mount board 108 for grounding purposes. As a result, the shielding shell 102 is grounded by way of the lead terminal 106.
The technique described in Japanese Patent Publication No. Hei. 5-3330 is exemplary of a related-art technology analogous to that mentioned above.
In an optical connector 110 shown in FIG. 32, ground tab pieces 113 are formed on both sides of a shielding shell 112 so as to jut outward from both sides of a main body section of a connector housing 115. The optical connector 110 is fixedly mounted on a mount board 118 such that the tab pieces 113 are brought, in an overlapped manner, into plane contact with ground traces 119 formed on an upper surface of the mount board 118. As a result, the shielding shell 112 is grounded by way of the tab pieces 113.
However, in the case of the optical connector 101 shown in FIG. 31, the shielding shell 102 is merely grounded by way of the pin-shaped lead terminal 106. Hence, high ground resistance arises, and an insufficient electromagnetic shielding effect is achieved.
Moreover, in this related-art and the similar related-art thereof, an optical element is fittingly inserted into a housing recess formed in a metal case; an opening of the housing recess is formed so as to become slightly larger than the element main body so that the element main body of the optical element can be fitted into the recess.
Accordingly, there is a chance of a slight clearance arising between an interior surface of the housing recess of the metal case and an exterior surface of the element main body. Such a clearance may, in turn, cause a drop in heat transfer efficiency.
In the case of the optical connector 110 shown in FIG. 32, the tab pieces 113 are brought into plane contact with the ground traces 119. Hence, low ground resistance arises, and a sufficient electromagnetic shielding effect is achieved. However, the ground tab pieces 113 significantly jut outward from both sides of the main body section of the connector housing 115. Hence, it becomes necessary to use a large area for fixedly mounting the connector 101.